Tape sensing device



Nov. 30, 1965 s. L. PASTOR ETAL 3,220,559

TAPE SENSING DEVICE Original Filed May 8, 1961 4 Sheets-Sheet l I 47Tnwsum PLAY STEREO RECORD \L It 4/ V-V 5 FIG. I

INVENTORS SHELDON LEE PASTOR CARL W. CLARAS RUDOLPH A. ROM

BY MW 5 1955 s. PASTOR ETAL 3,

TAPE SENS ING DEVI CE Original Filed May 8, 1961 4 Sheets-Sheet 2 o 5 ol R INVENTORS SHELDON LEE PASTOR CARL W. CLARAS RUDOLPH A. ROM

E BY 5 j i Rz EYs 1965 s. 1.. PASTOR ETAL 3,220,659

TAPE SENSING DEVICE Original Filed May 8. 1961 4 Sheets-Sheet 3 SHELDONLEE PASTOR FIG. 5 CARL w. CLARAS RUDOLPH A. ROM

Nov. 30, 1965 s. L. PASTOR ETAL 3,220,659

TAPE SENSING DEVICE Original Filed May 8, 1961 4 Sheets-Sheet 4 FIG. 8

INVENTORS SHELDON LEE PASTOR CARL W. CLARAS RUDOLPH A. ROM

ATTORNEYS United States Patent 3,220,659 TAPE SENSING DEVICE Sheldon LeePastor, St. Paul, Minn, and Carl W. Claras, Western Springs, and RudolphA. Rom, Napervilie, Iii, assignors to Minnesota Mining and ManufacturingCompany, St. Paul, Minn, a corporation of Delaware Original applicationMay 8, 1961, Ser. No. 108,352, now Patent No. 3,149,797, dated Sept. 22,1964. Divided and this application July 13, 1964, Ser. No. 382,322

6 Claims. (Cl. 24255.13)

This invention relates to improvements in self-threading magnetic taperecording and reproducing apparatus, and more particularly relates to asensing mechanism which is capable of automatically indicatingcompletion of the rewind operation of the apparatus.

This application is a division of application Serial No. 108,352, filedMay 8, 1961, now Patent No. 3,149,797, for Self-Treading Magnetic TapeRecording and Reproducing Apparatus.

The present invention provides a novel sensing means for an improvedautomatic recorder-reproducer which utilizes a relatively stiff leaderto thread the recording tape into said recorder-reproducer. The sensingmeans, being cooperable with the leader during a rewind operation andtaking advantage of the fact that the leader has a greater transversedimension than the limp magnetic tape to which it is attached, isoperable to permit free travel of the tape therepast, but tofrictionally engage the leader and to be moved by said engagementthrough a distance to do effective work during a rewind operation.

While the inventive concept has particular utility in the field ofmagnetic recording, the broader aspects of the invention are not solimited, it being obvious that various features thereof have substantialutility in other fields.

Advantages of the present invention other than afore stated will becomeapparent as the description proceeds, reference being had to thedrawings accompanying and forming a part of this specification, wherein:

FIGURE 1 is a plan view of the improved magnetic taperecorder-reproducer with one cover plate section removed to expose theparts therebelow.

FIGURE 2 is a fragmentary sectional plan view taken generally in theplane of the tape path and as indicated by the line 11-11 of FIGURE 5,the parts being shown in the position assumed thereby during threadingof the leader and tape;

FIGURE 3 is a fragmentary sectional plan view taken generally below theplane of the cartridge and takeup reel showing the parts in rewindposition;

FIGURE 4 is a fragmentary plan view of the mechanism for sensing thecompletion of a rewind operation, the parts of said mechanism being inthe normal positions they assume at all times except during rewinding ofthe tape and leader;

FIGURE 5 is a fragmentary vertical sectional view taken along the lineV-V of FIGURE 4;

FIGURE 6 is a fragmentary plan View similar to FIG- URE 4 showing theposition to which the parts are moved by passage of the leadertherethrough during rewinding of the tape and leader;

FIGURE 7 is a vertical sectional view taken along the line VIIVII ofFIGURE 6;

FIGURE 8 is a fragmentary elevational view of an extent of magnetic tapeshowing a leader attached to one end and a trailer attached to the otherend;

Referring more particularly to FIGURE 1 of the drawing, it will beobserved that the improved recorderreproducer comprises a generallyrectangular box-like case which removably encloses a chassis on whichthe component parts of the invention are mounted. The chassis comprisesan upper deck 2 and a lower deck "ice (not shown) vertically spacedtherefrom. As shown in FIGURE 2, the chassis includes at the rearthereof spaced parallel vertical plate or wall members 4 and 5 joined byspaced parallel vertical wall members 6 and 7 to provide a rectangularwell forming part of a cartridge storage and changer mechanism indicatedgenerally by the numeral 8. The improved recorder-reproducer alsoincludes an amplifier and a pair of speakers, neither of which will beshown or described and which may be of any suitable construction.

Power for operation of the mechanism of the improved recorder-reproduceris derived from an electrical motor 9 (see FIGURE 3) supported by thelower deck and having an upstanding drive shaft 10. As shown in FIG- URE3, the drive shaft 10 projects through the upper deck 2 and carries atits upper end a drive wheel 11, preferably having a rubber-likeperipheral ring 12. Mounted in suitable bearings in the upper and lowerdecks is a capstan shaft 13 which projects above the deck 2 and has afly wheel 14 fixed thereon between said decks as shown in FIGURE 3.Above the deck 2 the shaft 13 has a belt drive pulley 16 (FIGURE 3)fixed thereon. A suitably mounted idler drive wheel 17 affordscontinuous driving engagement between the motor drive shaft 10 and thefly wheel 14 to afford continuous clockwise rotation of the fly wheel14, capstan shaft 13 and belt drive pulley 16 whenever the motor 9 isoperating.

As shown in FIGURES 2 and 3, a vertical shaft 18, mounted in suitablebearings, projects above deck 2 and has a takeup reel 19 fixed to theupper end thereof. A clutch pulley 20 is freely rotatable on the shaft18 below the takeup reel 19 and is associated with the takeup reelthrough a clutch mechanism. A pulley 21 is freely rotatable on avertical shaft 22, and a pulley 23 is freely rotatable on a stub shaft24 carried by an arm 25 pivotally mounted on a vertical shaft 26. Apulley 27 is vfreely rotatable on a stub shaft 28 carried by an arm 29pivotally mounted on a vertical shaft 30. An endless belt 31, forexample of rubber-like material and of circular cross section, istrained around the pulleys 20, 21, 23, 16 and 27 as shown, so thatclockwise rotation of the capstan 13 produces clockwise rotation ofpulleys 20, 21 and 23, and counterclockwise rotation of the pulley 27.

The changer mechanism 8 is adapted to accommodate a cartridge 32(FIGURES 2 and 3) in play position therein. The cartridge 32 comprises ashallow rectangular container 33, for example of plastic, within which asup- .ply reel 34 is rotatably mounted. When the cartridge 32 is in playposition, the supply reel 34 is disposed in the same horizontal plane asthe takeup reel 19. The supply reel 34, illustrated in FIGURE 2,comprises a central hub portion 35 and spaced circular side flanges 36.

Referring to FIGURE 8, a relatively limp magnetic tape 37 has arelatively stiff flexible normally straight leader 38 having a trailingend 38a of the same Width as the tape 37. Major portion 38b of theleader 38 has a width greater than the spacing between the reel flanges36. A trailer 39 is attached to the other end of the tape 37 and has awidth substantially the same as that of said tape. The trailer 39 isstiffer than the said tape 37 but may be somewhat more flexible than thestiff normally straight leader. The free end of the trailer 39 isfixedly attached to the hub 35 of the reel 34, and said trailer,together with the tape 37 and the portion 38a of the leader is Wound onthe hub 35 between the flanges 36. The portion 38b of the leader, due toits greater width, is wound on the peripheries of the flanges 36 whenthe cartridge 32 is not in use.

An example of one type of magnetic recording tape which is satisfactoryfor use in the improved apparatus is one in which the backing or carrierfilm takes the form of tensilized polyethylene terephthalate .005 inchthick 3 and .150 inch wide. The leader 38 may be made of polyethyleneterephthalate .0101 inch thick, the portion 38a being .150 inch wide andthe portion 38b being .238 inch wide.

A lever 44 is mounted between the upper and lower decks for pivotalmovement on a shaft 45 depending from the deck 2 (FIGURE 3). The lever44 carries at one end a vertical shaft 46 which projects upwardlythrough a slot 47 (FIGURE 2) in the upper deck 2 and carries on itsupper end a freely rotatable drive-out rewind roller 48. As shown inFIGURE 2, the wall 4 of the chassis is formed with an opening 52 andwith an opening 53. When a cartridge 32 is in play position, an opening41 therein is in registry with the wall opening 53, and the flanges 36of the reel 34 thereof are disposed for engagement with thedn've-out-rewind roller 48. The lever 44 affords a swingable mountingfor the drive-out-rewind roller 48, said roller being movable from theretracted or inoperative position thereof shown in FIGURE-1, to theadvanced or operative position thereof shown in FIGURES 2 and 3, whereinthe roller engages the leader 38 wound on the periphery of the reelflanges 36 to push the leader out of the cartridge 32 and along apredetermined path to the takeup reel 19 as shown in FIGURE 2 during athreading operation and to engage the peripheries of the flanges 36during a rewind operation as will hereinafter appear.

Means i provided for effecting engagement of a forward drive orcounterclockwise rotational movement for the drive-out-rewind roller 48,disengagement of all drive for said roller or engagement of the rewinddrive for said roller as shown in FIGURE 3. To this end, an irregularlyshaped stamping 71 is mounted for pivotal movement above the deck. 2about the axis of the pulley shaft 22. The stamping 71 has a projection72 for coaction with the depending pin 64 on plate 62, and it also has alaterally projecting arm 73 formed with an upstanding lug 74 (FIGURE 3)for coaction with the arm 25 which supports the belt pulley 23. Thestamping 71 has three operative positions. In the intermediate positionthereof the upstanding lug 74 engages the arm 25 to hold the belt 31 outof driving engagement with the roller 48. At the same time, the bias ofthe spring 69 holds a rewind idler 61 out of engagement with thedrive-out-rewind roller 48 through a plate 62 and link 66. In theforward drive-out or thread position of the member 71 the upstanding lug74 has been withdrawn from the arm 25 sufliciently to permit engagementof the belt 31 with the drive-out-rewind roller 48 for counterclockwiserotation of the latter. At the same time, the action of the spring 69holds the rewind idler 61 out of engagement with the rollers 11 and 48.

The rewind position of the member 71 is shown in FIGURE 3. In thisposition the upstanding lug 74 engages the arm 25 and holds the latterin a position wherein the belt 31 is spaced substantially from thedrive-outrewind roller 48. At the same time, the projection 72 hasengaged the depending pin 64 on plate 62 and rotated said platecounterclockwise against the bias of the spring 69, such movement beingeffective through the link 66 and spring 68 to pull the rewind idler 61into driving engagement with both the drive roller 11 and thedrive-out-rewind roller 48 to thereby cause clockwise rotation of thelatter. The stamping 71 is formed with a laterally projecting arm 75which carries a cam following roller 76 through which the disposition ofthe stamping 71 is controlled as will hereinafter appear.

The takeup reel 19 comprises a hub portion 77, a

lower circular flange 79 and an annular member 80 of rubber-likematerial which snugly surrounds the said hub as shown in FIGURE 2. Acircular side flange 92, for example of clear plastic, overlies the hub77 and is formed with suitable openings and cutout portions to hold itin registry with the hub 77 and yet permit axial movement relativethereto against the bias of a spring,

not shown. An arcuate preferably circular deflecting and retainingmember is suitably mounted relative to the flanges 79 and 92 to disposeits cylindrical inner surface in spaced relation between the peripheralportions of the flanges 79 and 92 and coaxial therewith. As shown inFIGURE 2, the member 100 is formed with an opening 102 for passagetherethrough of the leader and tape.

The takeup reel 19 is provided with a suitable dual torque clutchmechanism which will provide a low torque driving connection between thepulley 20, the driving member of the clutch mechanism, and the takeupreel 19, a high torque driving connection or no rotative force. The lowtorque driving connection aforementioned applies a rotating force to thetakeup reel 19 which is less than that which can deleteriously stressthe magnetic tape 37.

A clutch actuating lever 117, as shown most clearly in FIGURE 3, has oneend apertured to receive a screw 118 threaded into the deck 2, therebeing a helical spring surrounding the screw 118 and holding theadjacent end of the lever 117 elevated against the head of said screwand spaced above the deck 2. The other end of the lever 117 isbifurcated as at 120, said bifurcated end embracing the shaft 18 andengaging the floating pulley 20. The lever 117 has a downwardly offsetportion 121 engagement of which with the deck 2 defines the lowermost,disengaged or off position of the drive pulley 20. Means is provided foractuating the clutch lever 117, and to this end a three-armed lever 122,pivoted on a pin 123, is provided which on one arm 124 carries a camfollowing roller 125.

A generally L-shaped lever 134 is pivotally mounted on a vertical pin135 and terminates at one end in a rounded, upturned flange 136 whichengages the underside of the clutch actuating lever 117. A lever arm 129of the lever 122 i provided with an enlarged end portion 130. Adownwardly offset circular portion 137 formed on the lever 134 isdisposed adjacent the end portion 130 and is adapted to engage the uppersurface of the end portion 130 as Well as the upper surfaces of upwardlyoffset portions 132 and 131 of the arm 129, to provide, when engagedwith said surfaces respectively, the off, the low torque and the hightorque positions of the lever 117 and clutch drive pulley 20.

The other end of the lever 134 is pivotally connected, as by pin 143, toa slide bar 138 which is slotted as at 139 and 140 to receive fixedguide pins 141 and 142. The slide bar 138 is movable longitudinallybetween 'a start position and a stop position to thereby effect movementof the lever 134 which in turn actuates a normally open switch 144. Inthe start position shown in FIGURE 3 the contacts of the switch areclosed.

Referring to FIGURES 2 and 3, an irregularly shaped arm 153 is pivotallymounted at one end on a fixed pin 154, and intermediate its length saidarm carries an upstanding stub shaft 155 on which a pressure roller 156of rubber-like material is freely rotatable, said roller beingcooperable with the capstan 13. The arm 153 has an end surface 157cooperable with a roller 55 and, as best shown in FIGURE 3, said arm hasa laterally projecting end portion 158 formed at one edge with a pair ofspaced upstanding lugs 159. The arm 153 is also formed with an L-shapedbranch arm 160 which carries a cam following roller 161 at its outerend. The arm 153 has two operative positions between which it can bemoved on the pivot 154, i.e., the advanced position thereof wherein thepressure roller 156 is in engagement with the capstan 13, and theretnacted position thereof shown in FIGURES 2 and 3. It will be observedthat when the arm 153 is in its retracted position, the drive-out andrewind roller 48 is advanced through the opening 52 in the wall 4 intoposition for engagement with the leader 38 wound on the periphery of thereel 34 or with said reel itself as shown in FIGURES 2 and 3. Uponadvancing movement of the arm 153, the end surface 157 coacts with aroller 55 to pivot the arm 44 and retract the drive-out-rewind roller 48from the opening 52 in wall 4 to the inoperative position.

Referring to FIGURE 3, an L-shaped crank member 162 is also pivoted onthe pin 154 and is formed at the end of one arm thereof with anupstanding lug 163 posi tioned for engagement with the adjacent edge ofthe arm 153. A tension spring 164 is connected at one end to the end ofthe other arm of crank 162, and the other end of said spring is suitablyanchored such that said spring biases the crank 162 in a clockwisedirection. The slide bar 138 is formed with a downturned lug 165 shownin dotted lines in FIGURE 3, and the spring 164 biases the adjacent armof the crank 162 into engagement with the lug 165 such that the crank162 follows the movement of the slide bar 138. Thus, upon retractilemovement of the slide bar 138 in response to depression of the stop key147 the crank 162 pivots to the dot and dash line position thereof shownin FIG- URE 3, and if the arm 153 is in advanced position at the time,the lug 163 on said crank arm engages the arm 153 and moves the same toits retracted position shown in FIGURE 3. A tension spring 166 isconnected at one end to the upstanding lug 163 on crank 162 and has itsother end connected to the branch arm 160 of the arm 153, as at 167. Thespring 166 is under continuous tension at all times.

Referring to FIGURES 2, 5 and 7, a pair of irregularly shaped guideplates 168 and 169 are vertically spaced a distance not substantiallygreater than the width of the magnetic tape, the inner surfaces of saidplates being disposed substantially coplanar with the inner surfaces ofthe takeup reel flanges 79 and 92. The plates 168 and 169 are formedwith straight line rectangular grooves 170 and 171, respectively, saidgrooves being of sufficient depth to accommodate the opposite edgeportions of the leader 38 and being operable to afford a predeterminedpath for said leader from adjacent the opening 53 in the wall 4'to theopening 102 in the annular guide and deflecting member 100 at the takeupreel 19. The aforementioned leader path passes between the capstan 13and the pressure roller 156 when the latter is retracted, as best shownin FIGURE 2. Offset from the path afforded by the grooves 170 and 171 amagnetic play-record head 172 and a magnetic erase head 173 are mounted,for example by suspension from a plate 174 fixed on the upper plate 168as shown in FIGURE 1. As shown in FIGURE 2, a pressure pad member 175 isdisposed between the guide plate 168 and 169 and is pivotally mounted atone end on a pin 176, said member carrying a pad 177, for example offelt at its other end. The member 175 carries a pin 178, and a tensionspring 179 is connected at one end to the pin 178 and is anchored to afixed pin 180 at its other end. The spring 179 thus biases the member175 counterclockwise toward a position with the pad engaging the erasehead 173.

The upper and lower guide plates 168 and 169 are formed with registeringarcuate slots 181 for accommodation of a pair of spaced vertical pins182 which depend from the end of an arm member 183 mounted for pivotalmovement on the axis of a vertical shaft 184. A spring loadedlost-motion connection is provided between the member 183 and the arm153 by a shaft 184, torsion spring 188 which surrounds the shaft, and ahorizontally directed pin 185 disposed on the shaft 184 between lugs 159on the arm 153.

When the arm 153 is in its retracted position shown in FIGURE 2, themember 183 is disposed in the position thereof shown in said figurewherein the pins 182 are disposed on opposite sides of the path affordedby the grooves 170 and 171 of the guide plates. When the member 183 isin the position shown in FIGURE 2, the outermost pin 182 engages thepressure pad member 175 to hold the same against the bias of the spring179 in the retracted position wherein said member and the pad 177 areout of the path of the leader and tape. An overcenter spring 189 has oneend connected to the member 183 and has its other end suitably anchoredto insure full travel of the member 183 to the position thereof shown inFIGURE 2. Advancing movement of the arm 153, acting through theupstanding lugs 159, pin 185 and torsion spring 188 tends to causeclockwise swinging movement of the member 183 to the position whereinthe pins 182 are disposed at the opposite end of the slots 181 to movethe tape to a play position relative to the heads 172 and 173.

Referring to FIGURES 1 and 2, the member 183 carries an angled bracket194 having an upstanding apertured flange for receiving a rod 195 whichis freely slidable therethrough and has an upturned end portionpreventing removal of said rod from said upstanding flange. The oppositeend of the rod 195 is connected to a button 196 (FIGURE 1) so thatactuation of said button toward the right when the member 183 is in theplay position thereof swings the member 183 toward the position thereofshown in FIGURE 2 with actuation of a switch 192 (FIGURE 1) and closureof the contacts thereof during such movement of the member 183.

Referring to FIGURES 1 and 4 to 7, the improved recorder-reproducerincludes sensing means operative during a rewind operation to sense thepassage of the leader into the cartridge. To this end, a pair ofupstanding apertured bracket members 197 and 198 are mounted on theupper guide plate 168 adjacent the wall 4, and a horizontal shaft 199 isaxially slidable on said brackets. A pair of cooperating sensing members200 and 201 are pivotally mounted on the shaft 199 and have inturned jawportions 202 and 203 disposed between the upper and lower guide plates168 and 169, said jaw portions terminating in rounded opposing inneredge surfaces shown most clearly in FIGURE 2. The jaw portion 202carries a depending pin 204 slidable in a slot 205 formed in the lowerguide plate 169 and parallel with the shaft 199. The coaction of the pin204 and slot 205 effects disposition of the inner edge surface of thejaw portion 202 adjacent one side of the guideway provided by thegrooves 170 and 171 in the plates 168 and 169 as shown in FIG- URES 4and 7.

The members 200 and 201 are formed on their upper ends with upstandingapertured lugs 206 and 207, and a screw 208 extends loosely through theaperture in the lug 206 and is threaded into the aperture in the lug207, there being a helical compression spring 209 surrounding the screw208 and biasing the lugs 206 and 207 apart toward the limit permitted byengagement of the head of the screw 208 with the lug 206. This limitaffords a spacing between the opposed edge surfaces of the jaw portion202 and 203 which is greater than one transverse dimension, for examplethe thickness, of the tape 37, but is somewhat less than thecorresponding transverse dimension, for example the thickness, of theleader 38. When a leader 38 is used is .010 inch thick, a satisfactoryminimum spacing between the opposing surfaces of the jaw portions 202and 203 may be .005 inch. The sensing members 200 and 201, together withthe shaft 199 are biased toward the right into engagement with thebracket 198 by a tension spring 210 having one end connected to thescrew 208 and having its other end suitably anchored.

The member 201 carries a pivotally mounted sear 211 biasedcounterclockwise to the position shown in FIG URES 4 and 6 by a lighttension spring 212 anchored at one end to said member. The sear 211 isprevented from rotating counterclockwise beyond its position shown inFIGURES 4 and 6 by virtue of its abutment with the lug 207. It can,however, pivot clockwise against the bias of the spring 212. A normallyopen switch 213 has a swingable actuating arm 214 which is biased to theposition thereof shown in solid lines in FIGURES 4 and 6 and is movablecounterclockwise from said position to effect closure of the contacts ofthe switch 213. Movement of the members 200 and 201 toward the left fromthe position of FIGURE 4 to that of FIGURE 6 moves the sear 211 intoengagement with and past the arm 214, said sear being pivoted clockwiseby such engagement and then returning to. its initial position uponclearing the arm 214. Upon subsequent return movement of members 200 and201 toward the right to the position of FIGURE-4 causes the sear 211 toengage the switch arm 214 and swing the latter to the dot and dash lineposition thereof shown in FIGURE 6 as said gear engages and then clearssaid switch arm without pivotal movement of said sear. Such actuation ofthe switch arm 214 effects closure of the contacts thereof, and upon thesear clearing said arm, the latter returns to its initial position andthe contacts of the switch 213 reopen.

Referring again to FIGURE 1, a generally U-shaped lever 215 is pivotallymounted on the upper end of the shaft 22 and has a rounded end portion216 positioned for coactionwith the upstanding lug 207 of sensing member201. The other end of the lever 215 carries a depending pin (not shown)to which is connected one end of a tension spring (disposed beneath saidother end in FIGURE 1) which has its other end connected to a pin 128carried by an upstanding arm portion 126 of the member 122. The tensionspring biases the lever 215 in a counterclockwise direction tending tomove said lever into engagement with the upstanding lug 127. Exceptduring a rewind operation, the tension spring biases the lever 215 tothe position shown in FIGURES 1, 4 and 5 wherein the end portion 216engages the upstanding lug 207 and pivots the member 201counterclockwise as viewed in FIGURE 5 about the shaft 199 and againstthe bias of the compression spring 209 to thereby withdraw the inneredge surface of the jaw member 203 from the inner edge surface of thejaw member 202 to provide a gap between said edge surfaces substantiallygreater than the thickness of the leader 38. Such pivotal movement ofthe member 201 moves the head of the screw 208 outof engagement with thelug 206 as shown in FIGURES 4 and 5. As will hereinafter appear, duringa rewind operation the upstanding lug 127 of the member 122 engages thelever 215 and pivots the latter clockwise to retract the end portion 216out of engagement with the upstanding lug 207, permitting return of themember 201 to the sensing position of FIGURE 7.

Movement of the lever 122, and of the arm 153 and lever 71 is under thecontrol of cams 219, 220 and 221 which are fixed on a vertical cam shaft222 and coact respectively with the cam following rollers 125, 161 and76. The cam shaft 222 is mounted in suitable bearings in the upper andlower decks. The cam 219 affords three positions of the follower 125 andtherefore of the lever 122. The innermost position of the follower 125effects disposition of the lever 122 in the rewind position thereofshown in FIGURE 3 with the clutch mechanism for the takeup reel 19disengaged.

The cam 220 affords two positions for the cam following roller 161 andthereby of the arm 153 carrying pressure roller 156. The inner positionof the follower 161 effects disposition of the lever 153 in its advancedposition wherein the pressure roller 156 engages the capstan 13. Theoutermost position of the follower 161 effects disposition of the arm153 in the retracted position thereof shown in FIGURES 2 and 3.

The cam 221 affords three positions for the cam following roller 76 andtherefore of the lever 71. When the follower 76 is in its outermostposition, the lever 71 is disposed in the rewind position thereof shownin FIGURE 3.

The cartridge storage and changer mechanism 8 provides for the automaticchanging of the cartridges 23 upon the tape in the same being threaded,played and rewoun by the apparatus. The changer mechanism is dividedinto two compartments or magazines. The magazines are designated as aload magazine 261 and a storage magazine 262 as shown in FIGURE 1. Themechanism 8 is controlled by cams on the stepping cam shaft 222 uponmovement thereof in response to completion of the rewinding as indicatedby operation of the switch 213 by the novel sensing means.

Operation After the leader 38 is threaded into the apparatus as shown inFIGURE 2, during the automatic cycle, and the tape reaches the capstan13, the parts shift to the play? position and the tape is withdrawn fromthe cartridge 32, past the heads 172 and 173 by the capstan 13 andpressure roller 156 and is wound on the takeup reel 19. The parts of theapparatus remain in the play or record position until all of the leaderand tape have been transported to the takeup reel and the trailer 39 iswound onto the takeup reel. When no more trailer is available forwithdrawal from the cartridge or supply reel 34, the pull exerted on thetrailer by the coaction of the pressure roller 156 and capstan 13 exertssubstantially increased tension on the portion of the trailer extendingbetween the capstan and the hub of the reel 34 to which the trailer 39is fixed. This increased tension, acts on the pins 182, to pull themember 183 from the play position toward the position of FIGURE 2.Switch 192 (FIGURE 1) is actuated during this movement by engagement ofthe projection 190 on the member 183 with the switch arm 191. Thiscauses the cam shaft 222 to rotate to a position to initiate rewindingof the trailer, tape and leader on the supply reel 34.

The movement of the cam shaft to begin rewind moves the follower to itsinnermost position to thereby move the member 122 to the rewind positionthereof shown in FIGURE 3 wherein the portion 137 of lever 134 is movedout of engagement with the raised surface portions 131 and 132 of thelever 122 to thereby disengage the clutch on the takeup reel andsimultaneously to move the upstanding lug 127 on the member 129 intoengagement with the adjacent end of the U-shaped lever '215 (FIGURE 1).Pivoting the lever 215 clockwise retracts the end 216 thereof from theupstanding lug 207 of the sensing member 201 as shown in FIGURES 6 and7. As shown in FIGURE 7, retraction of the end portion 216 from the lug207 causes clockwise movement of the member 201 about shaft 199 to bringthe inner edge surface of the jaw portion 203 thereof into minimumspaced relation with respect to the inner edge surface of the jawportion 202 of the member 200.

Movement of the cam 220 to rewin position causes movement of thefollower 161 to its outer position to cause retractile movement of thearm 153 and pressure roller 156 and simultaneous advancement of thedriveout-rewind roller 48 into engagement with the peripheries of theflanges 36 of the reel 34 while at the same time the arm 183 and pins182 are returned to the positions thereof shown in FIGURE 2.

Rotation of the cam 221 to the rewind position moves the follower 76 toits outermost position to thereby pivot the member 71 clockwise to itsrewind position shown in FIGURE 3, wherein the projection 72 on themember 71 engages the pin 64 and holds the triangular plate 62 rotatedcounterclockwise against the bias of spring 69 to the position thereofshown in FIGURE 3. Such positioning of the plate 62, acting throughv thelink 66 and spring 68 pulls the rewind idler 61 into engagement withboth the motor drive wheel 11 and the advanced driveout-rewind roller48. The roller 48 is rotated clockwise by the ,idler 61, and by virtureof its engagement with the reel flanges 36, it rotates the reel 34counterclockwise to effect high speed rewinding of the trailer 39, tape37 and leader 38 onto said reel. Such rewind, of course, causescounterclockwise rotation of the takeup reel 19 which is free to thusrotate, since the clutch thereof is disengaged.

The rewind operation continues until the leader 38 passes between thejaw portions 202 and 203 of sensing members 200 and 201 and is slidablygripped thereby to Cause movement of the sensing members against thebias of spring 210 to the position thereof shown in FIGURE 6. Uponmovement of the leader 38 out of engagement with the jaw portions 202and 203, the sensing members 200 and 201 return to the position thereofshown in FIGURE 4 under the bias of the spring 210, and in so doingactuate the switch 213 by engagement of the pawl 211 with the switch arm214. Closure of the switch 213 effects the continued rotation of the camshaft 222.

During the continued rotation of the cam shaft 222 the follower 125 ismoved to its outermost postion pivoting the member 122 to its positionwherein the portion 131, thereof is moved under the portion 137 of thelever 134 to engage the takeup reel clutch in high torque position. Suchmovement of the member 122 also withdraws the upstanding lug 127 fromthe U-shaped lever 215 to permit advancement of the end portion 216thereof into engagement with the upstanding lug 207 of sensing member201 for counterclockwise pivotal movement of said lever against the biasof spring 209 to the position thereof shown in FIGURE 5, such movementof the lever 215 being effected by the bias of the tension springbeneath the opposite end of the lever 215.

The continued rotation also moves the follower 161 to its inner positionto efiect advancing of the member 153 and pressure roller 156 andretractile movement of the drive-out-rewind roller 48. The member 71 isreturned to its intermediate position by follower 76 and then thechanger mechanism 8 is operative to shift the rewound cartridge 32 to astored position in magazine 262 and as may come within the scope of theappended claims.

What is claimed is:

' ,1. Means for sensing the travel of an extent of material along apredetermined path comprising a pair of sensing members having opposingsensing surfaces, means mounting said members adjacent said path formovement of the sensing surface of at least one of said members towardand away from the sensing surface of the other member and transverselyof said path and for movement of said members as a unit along said path,means biasing said at least one member in the direction to normallyposition said sensing surfaces closer together than the transversedimension of an extent of material to be sensed, stop means defining apredetermined first extreme position to which said members can move as aunit along said path and defining a predetermined second extremeposition to which said members can move as a unit in the oppositedirection along said path, said sensing surfaces being adapted to havesliding frictional engagement with transversely opposite surfaceportions of a said extent of material moved along said path between saidsurfaces, said engagement causing movement of said members as a unitwith said extent of material toward one of said extreme positions, andcontrol means operatively associated with said members and actuated bymovement of said members as a unit toward one of said extreme positions.

2. Means for sensing the travel of an extent of material along apredetermined path comprising a pair of sensing members having opposingsensing surfaces, means mounting said members adjacent said path formovement of the sensing surface of at least one of said members towardand away from the sensing surface of the other member and transverselyof said path and for movement of said members as a unit along said path,first biasing means biasing said at least one member toward the othermember to normally position said sensing surfaces closer together thanthe transverse dimension of an extent of material to be sensed, stopmeans defining a predetermined first extreme position to which saidmembers can move as a unit in one direction along said path and defininga predetermined second extreme position to which said members can moveas a unit in the opposite direction along said path, and second biasingmeans biasing said members as a unit toward said second position, saidsensing surfaces being adapted to have sliding frictional engagementwith transversely opposite surface portions of a said extent of materialmoved along said path between said surfaces in said one direction, saidengagement causing movement of said members as a unit with said extentof material against the bias of said second biasing means toward saidfirst extreme position, said members being returned as a unit by saidsecond biasing means toward said second extreme position upon continuedmovement of said material in said one direction out of engagement withsaid sensing surfaces.

3. A first extent of band material having a predetermined transversedimension and having attached to one end thereof a second extent of bandmaterial having a predetermined corresponding transverse dimensiongreater than that of said first extent, means for sensing the travel inone direction along a predetermined path of said second extent of bandmaterial comprising a pair of sensing members having opposing sensingsurfaces, means mounting said members adjacent said path for movement ofthe sensing surface of at least one of said members toward and away fromthe sensing surface of the other member transversely of said path andfor movement of said members as a unit along said path, means defining aminimum spacing between said sensing surfaces which is greater than saidtransverse dimension of said first extent to permit free travel of saidfirst extent therebetween along said path and less than the transversedimension of said second extent, first biasing means biasing said atleast one member in the direction tending to produce said minimumspacing between said sensing surfaces, stop means defining apredetermined first extreme position to which said members can move as aunit in said one direction along said path and defining a predeterminedsecond extreme position to which said members can move as a unit in theopposite direction along said path, and second biasing means biasingsaid members as a unit toward said second position, said sensingsurfaces being adapted to have sliding frictional engagement withtransversely opposite surface portions of said second extent when thelatter is moved along said path between said surfaces in said onedirection, said engagement causing movement of said members as a unitwith said second extent against the bias of said second biasing meanstoward said first position, said members being returned toward saidsecond position as a unit by said second biasing means upon movement ofsaid second extent out of engagement with said sensing surfaces.

4. In a machine having a supply reel, a takeup reel, and a rewind drivefor said supply reel, the combination of an extent of tape having oneend connected to the hub of said supply reel and having a leader ofgreater transverse dimension than said tape attached to the other end ofsaid tape, means defining a predetermined path for said tape and leaderbetween said reels, means adjacent said supply reel for sensingsubstantially complete rewinding of said tape and leader from saidtakeup reel onto said supply reel said sensing means, comprising a pairof sensing members having opposing sensing surfaces, means mounting saidmembers adjacent said path for movement of the sensing surface of atleast one of said members toward and away from the sensing surface ofthe other member transversely of said path and for movement of saidmembers as a unit along said path, first biasing means biasing said atleast one member in the direction to normally position said sensingsurfaces closer together than the transverse dimension of said leader,stop means defining a predetermined first extreme position to which saidmembers can move as a unit in said one direction along said path anddefining a predetermined second extreme position to which said memberscan move as a unit in the opposite direction along said path, and secondbiasing means biasing said members as a unit toward said secondposition, said sensing surfaces being adapted to have sliding frictionalengagement with transversely opposite surface portions of said leaderwhen the latter is moved along said path between said surfaces in saidone direction during a rewind operation, said engagement causingmovement of said members as a unit with said leader against the bias ofsaid second biasing means toward said first position, said members beingreturned toward said second position as a unit by said second biasingmeans upon movement of the free end of said leader past and out ofengagement with said sensing surfaces towards said supply reel.

5. In a machine having a supply reel, a takeup reel, and a rewind drivefor said supply reel, the combination of an extent of tape attached atone end to the hub of said supply reel and having a leader of greatertransverse dimension than said tape attached to the other end of saidtape, means defining a predetermined path for said tape and leaderbetween said reels, means adjacent said supply reel for sensingsubstantially complete rewinding of said tape and leader from saidtakeup onto said supply reel sensing means, comprising a pair of sensingmembers having opposing sensing surfaces, means mounting said membersadjacent said path for movement of the sensing surface of at least oneof said members toward and away from the sensing surface of the othermember transversely of said path and for movement of said members as aunit along said path, means defining a minimum spacing between saidsensing surfaces which is greater than the transverse dimension of saidtape to permit free travel of said tape therebetween along said path andless than the transverse dimension of said leader, first biasing meansbiasing said at least one member in the direction tending to producesaid minimum spacing between said sensing surfaces, stop means defininga predetermined first extreme position to which said members can move asa unit in said one direction along said path and defining apredetermined second extreme position to which said members can move asa unit in the opposite direction along said path, second biasing meansbiasing said members as a unit toward said second position, said sensingsurfaces being adapted to have sliding frictional engagement withtransversely opposite surface portions of said leader when the latter ismoved along said path between said surfaces in said one direction duringa rewind operation, said engagement causing movement of said members asa unit with said leader against the bias of said second biasing meanstoward said first position, said members being returned toward saidsecond position as a unit by said second biasing means upon movement ofthe free end of said leader past and out of engagement with said sensingsurfaces toward said supply reel, control means operatively associatedwith said members and with said rewind drive, and means for actuatingsaid control means to terminate operation of said rewind drive inresponse to return movement of said members to- Ward said secondposition.

6. Means for sensing the travel along a predetermined path of an extentof material having a transverse thickness discontinuity comprising apair of sensing members opposing sensing surfaces, means mounting saidmembers adjacent said path for movement of the sensing surface of atleast one of said members toward and away from the sensing surface ofthe other member transversely of said path and for movement of saidmembers as a unit along said path, means defining a minimum spacingbetween said sensing surfaces which is greater than the transversethickness of one portion of an extent of material to permit free travelof said one portion of said extent therebetween along said path and lessthan the transverse thickness of said extent at a second portion to besensed, first biasing means biasing said at least one member in thedirection tending to produce said minimum spacing between said sensingsurfaces, stop means defining a predetermined first extreme position towhich said members can move as a unit in said one direction along saidpath and defining a predetermined second extreme position to which saidmembers can move as a unit in the opposite direction along said path,second biasing means biasing said members as a unit toward said secondposition, said sensing surfaces being adapted to have sliding frictionalengagement with transversely opposite surfaces of said second portion ofa said extent when the latter is moved along said path between saidsurfaces, said engagement causing movement of said members as a unitwith said second portion against the bias of said second biasing meanstoward said first position, and said members being returned toward saidsecond position as a unit by said second biasing means upon movement ofsaid second portion out of engagement with said sensing surfaces.

No references cited.

MERVIN STEIN, Primary Examiner.

1. MEANS FOR SENSING THE TRAVEL OF AN EXTEND OF MATERIAL ALONG APREDETERMINED PATH COMPRISING A PAIR OF SENSING MEMBERS HAVING OPPOSINGSENSING SURFACES, MEANS MOUNTING SAID MEMBERS ADJACENT SAID PATH FORMOVEMENT OF THE SENSING SURFACE OF AT LEAST ONE OF SAID MEMBERS TOWARDAND AWAY FROM THE SENSING SURFACE OF THE OTHER MEMBER AND TRANSVERSELYOF SAID PATH AND FOR MOVEMENT OF SAID MEMBERS AS A UNIT ALONG SAID PATH,MEANS BIASING SAID AT LEAST ONE MEMBER IN THE DIRECTION TO NORMALLYPOSITION SAID SENSING SURFACES CLOSER TOGETHER THAN THE TRANSVERSEDIMENSION OF AN EXTENT OF MATERIAL TO BE SENSED, STOP MEANS DEFINING APREDETERMINED FIRST EXTREME POSITION TO WHICH SAID MEMBERS CAN MOVE AS AUNIT ALONG SAID PATH AND DEFINING A PREDETERMINED SECOND EXTREMEPOSITION TO WHICH SAID MEMBERS CAN MOVE AS A UNIT IN THE OPPOSITEDIRECTION ALONG SAID PATH, SAID SENSING SURFACES BEING ADAPTED TO HAVESLIDING FRICTIONAL ENGAGEMENT WITH TRANSVERSELY OPPOSITE SURFACEPORTIONS OF A SAID EXTENT OF MATERIAL MOVED ALONG SAID PATH BETWEEN SAIDSURFACES, SAID ENGAGEMENT CAUSING MOVEMENT OF SAID MEMBERS AS A UNITWITH SAID EXTENT OF MATERIAL TOWARD ONE OF SAID EXTREME POSITIONS, ANDCONTROL MEANS OPERATIVELY ASSOCIATED WITH SAID MEMBERS AND ACTUATED BYMOVEMENT OF SAID MEMBERS AS A UNIT TOWARD ONE OF SAID EXTREME POSITIONS.